JPWO2013058006A1 - Steering column support device - Google Patents

Abstract

The resistance at the time of tilting operation can be reduced in a state where the support rigidity of the swing bracket 28 by the tilt pivot shaft 15a can be sufficiently secured and the durability of the side plate portions 32c constituting the pair of bushes 30c is sufficiently secured. A steering column support device for an electric power steering device with a tilt mechanism that can be suppressed is realized. Of the outer peripheral surface of the tilt pivot shaft 15a and the inner peripheral surface of the insertion hole 29, portions that sandwich the cylindrical portion 31 constituting the bush 30c are defined as cylindrical surfaces. Further, in the neutral state where the assist reaction force is not generated on the outer surface of the side plate portion 32c constituting the bush 30c, the main contact surface portion 36 that contacts the inner side surface of the support plate portion 23, and in the neutral state A sub-contact surface portion 37 that is in non-contact with the support plate portion 23 and comes into contact with the inner surface of the support plate portion 23 only when an assist reaction force is generated and elastically deformed is provided as a thinning portion. [Selection] Figure 1

Description

  The present invention relates to an electric power steering apparatus having a tilt mechanism capable of adjusting the height position of a steering wheel, and more particularly to a steering column support apparatus for swingably supporting the steering column on the vehicle body side.

  Automobile steering devices usually incorporate a tilt mechanism that allows the height position of the steering wheel to be adjusted according to the physique and driving posture of the driver, and a telescopic mechanism that allows the front and rear position of the steering wheel to be adjusted. ing. In addition, it is widely practiced to incorporate an electric power steering apparatus that uses an electric motor as a power source so that a driver can reduce the force of operating a steering wheel. FIG. 25 shows a conventional example of an electric power steering apparatus including a tilt mechanism and a telescopic mechanism.

  The steering device includes a steering shaft 2 that fixes a steering wheel 1 at a rear end portion, a steering column 3 that rotatably supports the steering shaft 2 on its inner diameter side, and an electric assist for applying auxiliary torque to the steering shaft 2. A device 4 and a steering gear unit 6 for pushing and pulling a pair of left and right tie rods 5 based on the rotation of the steering shaft 2 are provided. In addition, the front-back direction in this specification means the front-back direction of a vehicle body.

  In the electric power steering apparatus, the steering shaft 2 can transmit a rotational force and can be axially displaced relative to the inner shaft 7 disposed on the front side and the outer shaft 8 disposed on the rear side. By combining the two, the structure can be expanded and contracted in the axial direction. Further, the steering column 3 has a structure capable of extending and contracting in the axial direction by combining the inner column 9 disposed on the front side and the outer column 10 disposed on the rear side so as to allow relative displacement in the axial direction. It has become. The outer shaft 8 is rotatably supported inside the outer column 10 in a state where axial displacement with respect to the outer column 10 is suppressed.

  A front end portion of the inner column 9 is coupled and fixed to a rear end surface of the housing 11 constituting the electric assist device 4. On the other hand, the inner shaft 7 is inserted into the housing 11, and a front end portion thereof is coupled to an input shaft constituting the electric assist device 4. Further, the front end portion of the output shaft 12 constituting the electric assist device 4 connected to the input shaft via a torsion bar protrudes from the front end surface of the housing 11, so that the universal joint 18, the intermediate shaft 19, and another universal shaft are provided. The joint 20 is connected to the input shaft 21 of the steering gear unit 6 via the joint 20.

  The inner column 9 is supported by a part of the vehicle body 14 via the housing 11 by the front support bracket 13. In order to realize the tilt mechanism, the front support bracket 13 swings the housing 11 around the tilt pivot shaft 15 supported by the front support bracket 13 and extending in the width direction of the vehicle body 14 (front and back in FIG. 25). Support movably.

  An intermediate portion of the outer column 10 is supported by a part of the vehicle body 14 by a rear support bracket 16. In order to realize the tilt mechanism and the telescopic mechanism, the outer column 10 has a fixed state in which the rear support bracket 16 cannot be moved back and forth and moved up and down, and a non-fixed state in which the back and forth movement and vertical movement are enabled. Supported to be switchable. Regarding such a support structure, various structures have been conventionally known and are not a feature of the present invention, and thus detailed description thereof will be omitted.

  In the case of such an electric power steering device, when adjusting the height position and the front-rear position of the steering wheel 1, the adjustment handle 17 (see FIG. 26) is rotated in a predetermined direction (usually downward). The intermediate portion of the outer column 10 is set in an unfixed state with respect to the rear support bracket 16. In this state, the height position of the steering wheel 1 is adjusted by swinging the steering column 3 about the tilt pivot shaft 15. Further, the front / rear position of the steering wheel 1 is adjusted by extending / contracting the steering column 3 and the steering shaft 2. After the adjustment, the adjustment handle 17 is rotated in the direction opposite to the predetermined direction (usually upward), thereby fixing the intermediate portion of the outer column 10 with respect to the rear support bracket 16.

  Further, when torque is applied from the steering wheel 1 to the steering shaft 2 during steering, the electric assist device 4 detects the direction and magnitude of this torque with a torque sensor provided in the housing 11, and detects the detected torque. Accordingly, the electric motor 22 supported on the outer surface of the housing 11 is configured to apply an auxiliary torque (assist force) to the output shaft 12 via a worm-type speed reducer provided in the housing 11. .

  In the electric power steering apparatus provided with such a position adjustment mechanism of the steering wheel 1, as described in Japanese Patent No. 3707252, the tilt pivot portion, which is the swing center portion of the steering column 3, is provided. The durability of this tilt pivot portion is improved by assembling the bush to the sliding portion. 26 to 31 show a first example of a conventional structure of a steering column support device for an electric power steering device in which a bush is assembled to a tilt pivot portion.

  The front support bracket 13a is made of a metal plate such as a steel plate, and is spaced apart in the width direction of the vehicle body 14 (the front and back directions in FIGS. 26 and 30 and the left and right directions in FIGS. 27, 28, and 29). It has a pair of support plate parts 23 parallel to each other. Further, the tilt pivot shaft 15 a is disposed in the width direction of the vehicle body 14 in a state of being spanned between portions near the lower ends of the pair of support plate portions 23. The tilt pivot shaft 15a includes a tilt bolt 24 made of a metal material such as steel, and a cylindrical sleeve 25 made of a metal material such as steel or aluminum alloy. The tilt bolt 24 is inserted into a pair of circular holes 26 provided concentrically with each other at the lower end portion of the pair of support plate portions 23, and is connected to a male screw portion provided at the distal end portion of the flange portion. The nut 27 is screwed and further tightened, so that the nut 27 is attached between the support plate portions 23. In addition, the sleeve 25 is clamped and fixed between the support plate portions 23 based on the tightening of the nut 27 in a state where the sleeve 25 is externally fitted to the flange portion of the tilt bolt 24.

  The housing 11a constituting the electric assist device 4a is made of a metal material such as an aluminum alloy, and a swing bracket 28 is integrally provided at a front end portion thereof. An insertion hole 29 is provided in the width direction of the vehicle body 14 at the tip of the swing bracket 28. The inner peripheral surface of the insertion hole 29 is configured by a stepped cylindrical surface in which the inner diameter dimension at both axial end portions is slightly larger than the inner diameter dimension at the axial intermediate portion. The axial end portions and the axial intermediate portion of the stepped cylindrical surface are concentric with each other. With the front end portion or intermediate portion of the swing bracket 28 being disposed between the support plate portions 23, the swing bracket 28 is inserted into the support plate via the tilt bolt 24 and the sleeve 25 that pass through the insertion hole 29. By being supported between the portions 23, the housing 11a and the steering column 3a are supported with respect to the front support bracket 13a so as to be able to swing around the tilt pivot shaft 15a.

  A pair of bushes 30 are externally fitted to both axial ends of the sleeve 25 constituting the tilt pivot shaft 15a. Each bush 30 is formed in a circular tube shape as a whole by an elastic material including a synthetic resin such as polyamide resin and an elastomer such as rubber or vinyl, or a low friction material such as an oil-containing metal. And an annular (outward flange-like) side plate portion 32 extending radially outward from one axial end of the cylindrical portion 31. The cylindrical portion 31 of the bush 30 is sandwiched between the axial end portions of the outer peripheral surface of the sleeve 25 and the axial end portions of the inner peripheral surface of the insertion hole 29 so that there is no rattling in the radial direction. Is done. The side plate portions 32 of the bush 30 are sandwiched between both side surfaces in the width direction of the swing bracket 28 and the inner side surface of the support plate portion 23 so that there is no backlash in the axial direction.

  In the case of such a conventional structure, since the bush 30 is assembled to both ends in the axial direction of the tilt pivot shaft 15a, the swing bracket 28 is centered on the tilt pivot shaft 15a when the height position of the steering wheel 1 is adjusted. The tilt pivot shaft 15a and the swing bracket 28 are not directly rubbed with each other, but the support plate portion 23 and the swing bracket 28 are also prevented from being rubbed directly. Therefore, it is possible to avoid a situation in which a gap that causes rattling is generated in the tilt pivot portion constituted by these members due to wear and plastic deformation that are caused by direct friction between these members.

  In the case of the electric power steering device, when the electric assist device 4a applies assist force to the output shaft 12a, the assist reaction force, which is the reaction force, is opposite to the rotation direction of the output shaft 12a with respect to the housing 11a. Join. As a result, the swing bracket 28 constituting the housing 11a receives an assist reaction force against the tilt pivot shaft 15a and the support plate portion 23, and tends to be displaced and inclined in a direction opposite to the rotation direction of the output shaft 12a. Become. At this time, the bush 30 supports the assist reaction force while being elastically compressed between the tilt pivot shaft 15a and the support plate portion 23 and the swing bracket 28 or being pressed in the compression direction. The displacement and inclination of the swing bracket 28 are suppressed. This prevents the swing bracket 28, the tilt pivot shaft 15a and the support plate portion 23 from rubbing directly.

  By the way, in the case of the first example of the conventional structure, the axial length of the cylindrical portion 31 is ensured in order to ensure the supporting ability of the anti-assist force by the bush 30, that is, the ability to suppress the displacement and inclination of the swing bracket 28. And the radial direction height of the side-plate part 32 is enlarged to some extent, respectively. Further, the inner side surface of the support plate portion 23 and both side surfaces of the swing bracket 28 and both side surfaces of the side plate portion 32 are all parallel planes. For this reason, in a neutral state where no assist force is generated, both side surfaces of the side plate portion 32, the inner side surface of the support plate portion 23, and both side surfaces of the swing bracket 28 are in contact with each other almost entirely. Therefore, both the inner and outer peripheral surfaces of the cylindrical portion 31 and the mating surface (the outer peripheral surface of the tilt pivot shaft 15a or the vibration) are increased by the amount of the axial length of the cylindrical portion 31 and the radial height of the side plate portion 32. The contact area with the inner peripheral surface of the insertion hole 29 of the moving bracket 28 and the contact between both side surfaces of the side plate portion 32 and the mating surface (the inner surface of the support plate portion 23 or both side surfaces of the swinging bracket 28). Each area is larger.

  On the other hand, in the case of the first example of the conventional structure, when the height position of the steering wheel 1 is adjusted, the swing bracket 28 swings about the tilt pivot shaft 15a, so that the cylinder constituting the bush 30 is formed. At the contact portion between at least one surface of the inner peripheral surface of the portion 31 and the outer surface of the side plate portion 32, and the outer peripheral surface of the cylindrical portion 31 and the inner surface of the side plate portion 32, and the mating surface facing this surface , Slipping in the circumferential direction occurs. Since the frictional force acting on the contact portion becomes resistance when adjusting the height position of the steering wheel 1, it is desirable that the frictional force be as low and stable as possible. However, since the contact area between the inner and outer peripheral surfaces of the cylindrical portion 31 and both side surfaces of the side plate portion 32 and the mating surface is increased, the frictional force acting on the contact portion between the surface of the bush 30 and the mating surface is increased. Under the influence of the properties of these mating surfaces, it becomes relatively high and unstable, and there is a possibility that the feeling of operation when adjusting the height position of the steering wheel 1 is deteriorated.

  On the other hand, FIGS. 32A and 32B show the second and third examples of the conventional structure of the steering column support device for the electric power steering device described in Japanese Patent Laid-Open No. 2008-30728. Is shown. In these structures, the inner peripheral surface of the insertion hole 29a formed in the swing bracket 28a is away from the outer peripheral surface of the cylindrical portion 31a constituting the bush 30a (30b) as it goes from the central portion in the axial direction to both ends. It is inclined to. As a result, substantially cylindrical gaps 33 each having a wedge-shaped cross section are provided on both sides of the axially central portion between the inner peripheral surface of the insertion hole 29a and the outer peripheral surface of the cylindrical portion 31a. . In the case of the second example of the conventional structure shown in FIG. 32A, the outer surface of the side plate portion 32a constituting the bush 30a is away from the inner surface of the support plate portion 23 as it goes radially outward. It is inclined to. Thus, a substantially annular gap 34 a having a wedge-shaped cross section is provided between the outer side surface of the side plate portion 32 a and the inner side surface of the support plate portion 23. On the other hand, in the case of the third example of the conventional structure shown in FIG. 32B, the direction in which the inner side surface of the side plate portion 32b constituting the bush 30b moves away from the outer side surface of the swinging bracket 28a as it goes radially outward. It is inclined to. Thus, a substantially annular gap 34b having a wedge-shaped cross section is provided between the inner surface of the side plate portion 32a and the outer surface of the swing bracket 28a. Based on the presence of the gaps 33, 34a, 34b thus provided, the swing bracket 28a (the central axis of the insertion hole 29a) is easily inclined with respect to the central axis of the tilt pivot shaft 15a.

  Due to the shape error of the front support bracket 13a and the rear support bracket 16a, the mounting error with respect to the vehicle body 14 (see FIG. 26), etc., the middle of the steering column 3a (see FIG. 26) by the rear support bracket 16a during the tilting operation. The guide direction of the part may be inclined with respect to a virtual plane orthogonal to the central axis of the tilt pivot shaft 15a. In the second and third examples of the conventional structure, even in such a case, the swinging bracket 28a is inclined with respect to the central axis of the tilt pivot shaft 15a. The swinging direction of the steering column 3a at the time of adjustment and the guide direction of the intermediate portion of the steering column 3a are in agreement with each other. Therefore, it is possible to avoid a situation in which the adjustment operation of the height position of the steering wheel 1 becomes poor due to the mismatch between the swing direction and the guide direction.

  Further, in the case of the second and third examples of the conventional structure, the contact area between the inner peripheral surface of the insertion hole 29a and the outer peripheral surface of the cylindrical portion 31a is small based on the presence of the gap 33. For this reason, the frictional force which acts between the internal peripheral surface of the through-hole 29a and the outer peripheral surface of the cylindrical part 31a can be made small. Further, based on the presence of the gaps 34a and 34b, in the second example of the conventional structure, the contact surface pressure between the both side surfaces of the swing bracket 28a and the inner surfaces of the side plate portions 32a and 32b (see FIG. 32A). In the third example of the conventional structure, these contact areas (see FIG. 32B) can be reduced. Therefore, the frictional force acting between them can be stably reduced, and the height position of the steering wheel 1 can be adjusted by causing slippage between the swing bracket 28a and the bushes 30a, 30b. It is possible to improve the workability of the height position adjustment by keeping the resistance when performing the operation low.

  However, in the second and third examples of the conventional structure, the support rigidity of the swing bracket 28a by the tilt pivot shaft 15a is reduced based on the presence of the gap 33, and the steering wheel 1 (see FIG. 25) is reduced. Support rigidity is also lowered. As a result, the driver may feel uncomfortable. Further, due to the assist reaction force generated at the time of steering, the swing bracket 28a is relatively inclined with respect to the central axis of the tilt pivot shaft 15a based on the presence of the clearance 33 among the clearances 33, 34a, 34b. To do. This may also cause the driver to feel uncomfortable.

Japanese Patent No. 3707252 JP 2008-30728 A

  In view of the circumstances as described above, the present invention secures the supporting ability of the anti-assist force by the pair of bushes, and adjusts the height position of the steering wheel, and the surfaces of these bushes. An object of the present invention is to realize a structure of a steering column support device for an electric power steering device that can stably suppress the frictional force acting between the opposite surface and the opposite surface.

  The steering column support device of the present invention is particularly applied to an electric power steering device provided with a tilt mechanism. The steering column support device of the present invention includes a front support bracket, a tilt pivot shaft, a swing bracket, and a pair of bushes.

  The front support bracket includes a pair of support plate portions that are fixed to the vehicle body and arranged in parallel to each other in the width direction of the vehicle body. The tilt pivot shaft is disposed in the width direction of the vehicle body in a state of being spanned between the support plate portions. Further, the swing bracket is provided in a part of the housing of the electric assist device, has an insertion hole through which the tilt pivot shaft is inserted, and supports a steering column that rotatably supports the steering shaft via the housing. To do.

  The pair of bushes are made of an elastic material or a low friction material, and are entirely formed in an annular shape. The bushes are respectively fitted on both ends in the axial direction of the tilt pivot shaft, and each is a cylinder sandwiched between the outer peripheral surface of the tilt pivot shaft and the inner peripheral surface of the insertion hole. And an annular side plate portion that extends radially outward from one axial end portion of the cylindrical portion and is sandwiched between a side surface of the swing bracket and an inner side surface of the support plate portion. In each of these bushes, at least in a neutral state where the assist force applied to the steering shaft by the electric assist device is not generated, a part of at least one of the peripheral surfaces of the cylindrical portion, or A part of at least one of both side surfaces of the side plate portion is provided with a thinning portion that is in a non-contact state with a mating surface facing these surfaces.

  In one aspect of the present invention, the thinning portion is constituted by a recess provided on at least one of both side surfaces of the side plate portion.

  In this case, in each of the bushes, at least one radial half of at least one of both side surfaces of the side plate portion is formed with a main contact surface portion that contacts the mating surface at least in the neutral state. In the other half of the direction, at least in the neutral state, the secondary contact surface portion that does not contact the counterpart surface and contacts the counterpart surface only when the side plate portion is elastically deformed by the reaction force of the assist force. The concave portion can be formed by the sub contact surface portion. In this configuration, the main contact surface portion can be provided on the inner diameter side, and the sub contact surface portion can be provided on the outer diameter side. However, conversely, the main contact surface portion can be provided on the outer diameter side, and the sub contact surface portion can be provided on the inner diameter side.

  Alternatively, the concave portion can be provided in at least one radial intermediate portion of both side surfaces of the side plate portion. In this case, the concave portion is provided at a plurality of locations in the circumferential direction of at least one of the both side surfaces of the side plate portion, and is a concave groove extending in the radial direction, or at least one of both side surfaces of the side plate portion. It can be constituted by a concave groove extending in the circumferential direction. The concave groove can be formed over the entire circumference of at least one of the side surfaces of the side plate portion. However, this ditch | groove can also be comprised by the several circular arc-shaped ditch | groove arrange | positioned in the circumferential direction.

  In another aspect of the present invention, the thinning portion is formed so as to penetrate through the thickness direction at least in one circumferential direction of at least one of the cylindrical portion and the side plate portion. In this case, the thinning portion is a discontinuous portion in which at least one of the cylindrical portion and the side plate portion is discontinuous in at least one circumferential direction, the cylindrical portion and the side plate. It can be configured by a notch that opens to at least one end edge of the portion, or a through hole that penetrates in the thickness direction of at least one of the cylindrical portion and the side plate portion.

  In the steering column support device of the present invention, the diameter of the portion of the outer peripheral surface of the tilt pivot shaft and the inner peripheral surface of the insertion hole that holds the cylindrical portion of the bush does not change in the axial direction. It is preferable that each cylindrical portion of the bush is supported as a cylindrical surface without rattling between the outer peripheral surface of the tilt pivot shaft and the inner peripheral surface of the insertion hole.

  According to the steering column support device of the present invention, even when the supporting ability of the counter-assist force by the pair of bushes is ensured, when adjusting the height position of the steering wheel, the surface of these bushes (the circumference of the cylindrical portion). The frictional force acting between the surface and the side surface of the side plate portion) and the opposing surface facing this surface can be stably kept low. In other words, at least a part of the peripheral surface of the cylindrical surface constituting the bush or the side surface of the side plate portion is in a neutral state where at least assist force is not generated, and is in a non-contact state with a mating surface facing these surfaces. It has a thinning part. For this reason, the contact area between the surface of the bush and the mating surface is reduced when the contact area between the surface of the bush and the mating surface is reduced by the thickness of the thinned portion, and becomes a resistance when adjusting the height position of the steering wheel. The frictional force acting on the steering wheel is stably kept low, thereby improving the workability of adjusting the height position of the steering wheel.

FIG. 1 is an enlarged view showing a tilt pivot portion of a first example of an embodiment of the present invention in a cut state. FIG. 2 is an enlarged view of part a in FIG. FIG. 3 is a view similar to FIG. 2 showing a second example of the embodiment of the present invention. FIG. 4 is a view similar to FIG. 2, showing a third example of the embodiment of the present invention. FIG. 5 is a view similar to FIG. 2, showing a fourth example of the embodiment of the present invention. FIG. 6 is a view similar to FIG. 28, showing a fifth example of the embodiment of the present invention. FIG. 7 is an enlarged view of part b of FIG. FIG. 8 is a view of the bush incorporated in the fifth example of the embodiment of the present invention as seen from the outer surface side of the side plate portion. FIGS. 9A to 9C are views showing three examples of concave portions provided on the side surface of the side plate portion, which can be incorporated in the fifth example of the embodiment of the present invention. FIG. 10 is a view similar to FIG. 7, showing a sixth example of the embodiment of the present invention. FIG. 11 is a view similar to FIG. 7, showing a seventh example of the embodiment of the present invention. FIG. 12 is a view similar to FIG. 1, showing an eighth example of the embodiment of the present invention. 13 is a cross-sectional view taken along the line cc of FIG. FIG. 14 (A) is a side view of the bush incorporated in the eighth example of the embodiment of the present invention, and FIG. 14 (B) is a view seen from the right side of FIG. 14 (A). 15A is a cross-sectional view (a cross-sectional view taken along the line dd in FIG. 15B) of the bush incorporated in the ninth example of the embodiment of the present invention, and FIG. 15B is a cross-sectional view of FIG. It is the figure seen from the right side. FIG. 16 is a view similar to FIG. 14 showing a bush incorporated in the tenth example of the embodiment of the present invention. FIG. 17 is a view similar to FIG. 14 showing a bush incorporated in the eleventh example of the embodiment of the present invention. FIG. 18 is a view similar to FIG. 14 showing a bush incorporated in the twelfth example of the embodiment of the present invention. FIG. 19 is a view similar to FIG. 14 showing a bush incorporated in the thirteenth example of the embodiment of the present invention. FIG. 20 is a view similar to FIG. 14 showing a bush incorporated in the fourteenth example of the embodiment of the present invention. FIG. 21 is a view similar to FIG. 14 showing a bush incorporated in the fifteenth example of the embodiment of the present invention. FIG. 22 is a view similar to FIG. 14 showing a bush incorporated in the sixteenth example of the embodiment of the present invention. FIG. 23 is a view similar to FIG. 14 showing a bush incorporated in the seventeenth example of the embodiment of the present invention. FIG. 24 shows a structure reference in which the force required to adjust the height position of the steering wheel can be reduced, and the amount by which the swing bracket tilts with respect to the center axis of the tilt pivot shaft can be suppressed by the assist reaction force. It is a figure similar to FIG. 2 which shows an example. FIG. 25 is a schematic side view showing an example of a conventional structure of an electric power steering apparatus provided with a tilt mechanism in a state where a part thereof is cut. FIG. 26 is a side view of an essential part showing a first example of a conventional structure of a steering column support device. FIG. 27 is a view from the left of FIG. 26, showing the tilt pivot portion in a cut state. FIG. 28 is an enlarged view of part e in FIG. FIG. 29 is an enlarged view of part f in FIG. 30 is a cross-sectional view taken along the line gg of FIG. FIG. 31 is a view similar to FIG. 14 showing the bush incorporated in the first example of the conventional structure. FIG. 32 (A) is a view similar to FIG. 29 showing a bush incorporated in the second example of the conventional structure of the steering column support device, and FIG. 32 (B) is a third view of the conventional structure of the steering column support device. It is a figure similar to FIG. 29 which shows the bush integrated in an example.

[First example of embodiment]
1 to 2 show a first example of an embodiment of the present invention. The steering column support device of the present invention is particularly applied to an electric power steering device provided with a tilt mechanism. The steering column support device of the present invention includes a front support bracket 13a, a tilt pivot shaft 15a, a swing bracket 28, and a pair of bushes 30c. The front support bracket 13a has a pair of support plate portions 23 that are fixed to the vehicle body and arranged in parallel with each other in the width direction of the vehicle body. The tilt pivot shaft 15a is disposed in the width direction of the vehicle body in a state of being spanned between the support plate portions 23. The swing bracket 28 is provided in a part of the housing of the electric assist device, and has an insertion hole 29 through which the tilt pivot shaft 15a is inserted. Each bush 30c is made of an elastic material including a synthetic resin such as a polyamide resin and an elastomer such as rubber or vinyl or a low friction material such as an oil-impregnated metal. A cylindrical portion 31 that is externally fitted to both axial ends of the pivot shaft 15a and is sandwiched between the outer peripheral surface of the tilt pivot shaft 15a and the inner peripheral surface of the insertion hole 29; The ring-shaped side plate portion 32c extends radially outward from one end portion in the axial direction and is sandwiched between the side surface of the swing bracket 28 and the inner surface of the support plate portion 23. The feature of this example is the shape of the outer surface of the side plate portion 32c of each bush 30c and the structure of the installation location of the cylindrical portion 31 of the bush 30c. The structure and operation of the other parts are the same as in the first example of the conventional structure.

  In the case of this example, of the both side surfaces of the side plate portion 32c of the bush 30c, the inner side surface facing the both side surfaces of the swing bracket 28 is a single ring surface. On the other hand, step portions 35 are formed on the inner peripheral portions of the outer surfaces facing the inner surfaces of the pair of support plate portions 23 constituting the front support bracket 13a among the both side surfaces of the side plate portion 32c. ing. As a result, the outer side surface of the side plate portion 32c is positioned on the inner side in the axial direction with respect to the inner side portion which is the other half portion of the radially opposite side portions sandwiching the step portion 35. It is a stepped ring with a stepped back. The inner diameter side portion of the both radial side portions sandwiching the step portion 35 is a single ring-shaped main contact surface portion 36, and the outer diameter side portion is concentric with the main contact surface portion 36 and has a single annular shape sub-portion. The contact surface portion 37 is used. Then, in the neutral state where the assist reaction force is not acting, as shown in FIGS. 1 and 2, almost the entire inner surface of the side plate portion 32 c is brought into contact with both side surfaces of the swing bracket 28. On the other hand, the outer side surface of the side plate portion 32 c makes only the main contact surface portion 36 of the radially inner portion contact the inner side surface of the support plate portion 23. That is, in this state, of the outer surface of the side plate portion 32c, the sub-contact surface portion 37 of the radially outer portion is not in contact with the inner side surface of the support plate portion 23, and with respect to the inner side surface of the support plate portion 23, It is opposed through a small gap.

  On the other hand, the cylindrical portion 31 constituting the bush 30c is a cylindrical surface whose diameter does not change with respect to the axial direction, both axial end portions of the outer peripheral surface of the sleeve 25 constituting the tilt pivot shaft 15a, and the swing bracket 28. The insertion hole 29 is sandwiched between both ends of the inner peripheral surface in the axial direction. That is, in the neutral state, as shown in FIGS. 1 to 2, almost the entire inner and outer peripheral surfaces of the cylindrical portion 31 (at least portions excluding the chamfered portions on both the radially inner and outer peripheral edges of both axial end portions) are the sleeves. In this state, both end portions of the outer peripheral surface of 25 and both end portions of the inner peripheral surface of the insertion hole 29 are in contact with no gap.

  According to the steering column support device of this example, the support rigidity of the swing bracket 28 by the tilt pivot shaft 15a can be sufficiently secured, and the swing bracket 28 is made to be the central axis of the tilt pivot shaft 15a by the assist reaction force generated at the time of steering. Can be sufficiently suppressed. Moreover, the resistance at the time of adjusting the height position of the steering wheel 1 (see FIG. 25) can be kept low in a state where the durability of the side plate portion 32c constituting the bush 30c is sufficiently ensured.

  That is, in the case of this example, of the outer peripheral surface of the sleeve 25 constituting the tilt pivot shaft 15a and the inner peripheral surface of the insertion hole 29, the portions sandwiching the cylindrical portion 31 constituting the bush 30c are respectively axially A cylindrical surface whose diameter does not change. And, in a neutral state, these cylindrical surfaces are respectively removed from the entire inner and outer peripheral surfaces of the cylindrical portion 31 (at least portions excluding the chamfered portions at both ends) except for a minute gap necessary for relative rotation, It is in contact with almost no gap. Therefore, the support rigidity of the swing bracket 28 by the tilt pivot shaft 15a can be sufficiently secured. Further, when the swing bracket 28 tends to be inclined with respect to the central axis of the tilt pivot shaft 15a due to the assist reaction force, the assist reaction force can be efficiently supported by the cylindrical portion 31. For this reason, this amount of inclination can be suppressed sufficiently low.

  In the case of this example, in the neutral state in which the height position of the steering wheel 1 is adjusted, the outer side surface of the side plate portion 32c constituting the bush 30c is mainly in relation to the inner side surface of the support plate portion 23. Contact is made only at the contact surface portion 36, but not at the sub contact surface portion 37. For this reason, in the neutral state, the contact area between the outer surface of the side plate portion 32c and the inner surface of the support plate portion 23 is reduced, and the frictional force acting on the contact portion between these outer surface and inner surface is reduced. Can do. Therefore, when the height position of the steering wheel 1 is adjusted, the resistance when adjusting the height position of the steering wheel 1 is reduced by sliding the outer surface of the side plate portion 32c and the inner surface of the support plate portion 23. It can be kept low.

  Further, in the case of this example, the swinging bracket 28 is displaced toward one of the support plate portions 23 of the pair of support plate portions 23 by the assist reaction force, and the center axis of the tilt pivot shaft 15a. When the inclination tends to be inclined, at least a part of the side plate portion 32c in the circumferential direction is pushed by the both side surfaces of the swing bracket 28 to be elastically deformed. As a result, the outer surface of the elastically deformed portion of the side plate portion 32 c comes into contact with the inner surface of the support plate portion 23 not only at the main contact surface portion 36 but also at the sub contact surface portion 37. For this reason, with respect to the side plate portion 32 c, the assist reaction force can be supported in a wide range including not only a portion corresponding to the main contact surface portion 36 but also a portion corresponding to at least a part of the sub contact surface portion 37. Further, as the swing bracket 28 is displaced, the support plate 23 is deformed. Due to the deformation of the support plate portion 23, the outer diameter side of the side plate portion 32 c is more strongly compressed by the deformation of the support plate portion 23. However, in the case of this example, since the escape by the sub-contact surface portion 37 is made in this portion, the abnormal wear of the side plate portion 32c is prevented. Therefore, it is possible to suppress the sag of the side plate portion 32c due to the repeated load of the assist reaction force, sufficiently ensure the durability of the side plate portion 32c, and prevent the occurrence of rattling in the tilt pivot portion for a long period of time. .

[Second Example of Embodiment]
FIG. 3 shows a second example of the embodiment of the present invention. In the case of this example, with respect to each of the pair of bushes 30d, the configuration of both side surfaces of the side plate portion 32d is reversed from the case of the first example of the embodiment. That is, in the case of this example, the outer side surface of the side plate portion 32d is a single ring surface, and the inner side surface of the side plate portion 32d is the main contact surface portion 36a on the inner diameter side and the sub contact surface portion 37a on the outer diameter side. It is set as the stepped ring surface which continued through the step part 35a. Then, in the neutral state where the assist reaction force is not acting, as shown in FIG. 3, the entire outer side surface of the side plate portion 32d is brought into contact with the inner side surface of the support plate portion 23, and the inner side surface of the side plate portion 32d is Of these, only the main contact surface portion 36 a is in contact with the side surface of the swing bracket 28. Also in the case of this example, based on the presence of the main contact surface portion 36a and the sub contact surface portion 37a, the same operational effects as in the case of the first example of the embodiment can be achieved. The structure and operation of the other parts are the same as in the first example of the embodiment.

[Third example of embodiment]
FIG. 4 shows a third example of the embodiment of the present invention. In the case of this example, regarding each of the pair of bushes 30e, the configuration of the sub-contact surface portion 37b provided on the outer diameter side portion of the outer surface of the side plate portion 32e is different from that of the first example of the embodiment. Yes. That is, in the case of this example, the inner peripheral edge of the sub-contact surface portion 37b is directly connected to the outer peripheral edge of the main contact surface portion 36 provided on the inner diameter side portion without a stepped portion. Further, the sub-contact surface portion 37b is an inclined surface that is inclined in a direction away from the inner surface of the support plate portion 23 as it goes outward in the radial direction. In the case of this example, the cross-sectional shape of the sub-contact surface portion 37b that is an inclined surface is a linear shape, but this cross-sectional shape is curved in a direction that is convex with respect to the inner surface of the support plate portion 23. It can also be a curved shape.

  In the case of this example, the main contact surface portion 36 provided on one side surface of the side plate portion 32e constituting the bush 30e is a plane parallel to the mating surface, and the sub-contact surface portion 37b is further away from the mating surface as it goes radially outward. The inclined surface is inclined in the direction of leaving. However, the entire one side surface of the side plate portion is an inclined surface that inclines in a direction away from the mating surface as it goes outward in the radial direction, and the portion that contacts the mating surface in the neutral state is the main contact surface portion. The portion that does not come into contact with the mating surface can be used as the sub-contact surface portion. Other configurations and operations are the same as those in the first example of the embodiment.

[Fourth Example of Embodiment]
FIG. 5 shows a fourth example of the embodiment of the present invention. In the case of this example, the configuration of the sub-contact surface portion 37c provided on the outer diameter side portion of the inner side surface of the side plate portion 32f is different from that of the second example of the embodiment for each of the pair of bushes 30f. Yes. That is, in the case of this example, the inner peripheral edge of the sub-contact surface portion 37c is directly connected to the outer peripheral edge of the main contact surface portion 36a provided on the inner diameter side portion without a stepped portion. Further, the sub-contact surface portion 37c is an inclined surface that is inclined in a direction away from the side surface of the swing bracket 28 as it goes outward in the radial direction. Other configurations and operations are the same as those in the second and third examples of the embodiment.

[Fifth Example of Embodiment]
6 to 8 show a fifth example of the embodiment of the present invention. In the case of this example, an annular groove 38 that is continuous over the entire circumference is provided concentrically with the side plate portion 32g in the radially intermediate portion of the outer side surface of both side surfaces of the side plate portion 32g constituting the bush 30g. . Then, at least in a neutral state where the assist reaction force is not acting, only the portion of the outer surface of the side plate portion 32g that is out of the concave groove 38 is brought into contact with the inner surface of the support plate portion 23.

  According to the steering column support device of the present example, in order to secure the support capability of the counter-assist force by the side plate portion 32g constituting the bush 30g, even when trying to sufficiently secure the radial height of the side plate portion 32g, it is neutral. In this state, the contact area between the outer side surface of the side plate portion 32 g and the inner side surface of the support plate portion 23 can be suppressed by the opening area of the groove 38. For this reason, it acts on the contact portion between the outer side surface of the side plate portion 32g and the inner side surface of the support plate portion 23 in the neutral state, which becomes resistance when adjusting the height position of the steering wheel 1 (see FIG. 25). The frictional force can be stably reduced. Therefore, it is possible to avoid a situation in which the frictional force is large and unstable, and workability when the height position of the steering wheel 1 is adjusted is deteriorated.

  Further, even when the outer plate side of the side plate portion 32c is strongly compressed by the deformation of the support plate portion 23, the outer plate end portion of the side plate portion 32c is bent because the concave groove 38 is formed in the side plate portion 32c. It is easy to absorb the deformation of the side plate portion 32c, and abnormal wear of the side plate portion 32c is prevented. Therefore, it is possible to suppress the sag of the side plate portion 32c due to the repeated load of the assist reaction force, sufficiently ensure the durability of the side plate portion 32c, and prevent the occurrence of rattling in the tilt pivot portion for a long period of time. .

  In addition, when implementing this example, grease is applied to the surface of the bush 30g, the surface of the bush 30g (both inner and outer peripheral surfaces of the cylindrical portion 31 and both side surfaces of the side plate portion 32g), and a mating surface facing this surface The frictional force acting on the contact portions with the inner peripheral surface of the insertion hole 29 and the outer peripheral surface of the sleeve 25, and the inner surface of the support plate 23 and both side surfaces of the swing bracket 28 can also be reduced. In this case, since the concave groove 38 can be used as a grease reservoir, the amount of grease retained can be increased by that much, and the effect of reducing the frictional force can be retained for a long time. Moreover, the number of the annular concave grooves provided on the side surface of the side plate portion 32g can be plural. Furthermore, a plurality of annular grooves having different diameters can be arranged in an annual ring shape, preferably concentrically.

  In addition, as a recessed part provided in the side surface of the side-plate part which comprises a bush, it is not restricted to the annular recessed groove 38 continued over the perimeter, About the circumferential direction as shown to FIG. 9 (A) and FIG. 9 (B). A plurality of arc-shaped concave grooves 38a that are long in the circumferential direction, a plurality of concave grooves 38b that are long in the radial direction, and are provided at regular intervals in the circumferential direction as shown in FIG. 9C. It is also possible to adopt a structure such as a round recess 39. Other configurations and operations are the same as those of the first example of the embodiment of the present invention and the first example of the conventional structure.

[Sixth Example of Embodiment]
FIG. 10 shows a sixth example of the embodiment of the present invention. In the case of this example, annular concave grooves 38c that are continuous over the entire circumference are formed in the radially intermediate portion of the inner side surface (the side surface on the swing bracket 28 side) of the side plate portion 32h constituting the pair of bushes 30h. Are provided concentrically with the side plate portion 32h. In the neutral state in which no assist reaction force is generated, only the portion of the inner side surface of the side plate portion 32 h that is out of the concave groove 38 c is brought into contact with both side surfaces of the swing bracket 28.

  Even in the case of the steering column support device of this example, in order to secure the supporting ability of the counter-assist force by the side plate portion 32h constituting the bush 30h, even when the radial height of the side plate portion 32h is sufficiently secured, The contact area between the inner side surface of the side plate portion 32h and both side surfaces of the swing bracket 28 can be suppressed by the opening area of the concave groove 38c. For this reason, it acts on the contact portion between the inner side surface of the side plate portion 32h and both side surfaces of the swinging bracket 28 in the neutral state, which becomes resistance when adjusting the height position of the steering wheel 1 (see FIG. 25). The frictional force can be stably reduced. Other configurations and operations are the same as those in the fifth example of the embodiment.

[Seventh example of embodiment]
FIG. 11 shows a third example of the embodiment of the present invention. In the case of this example, the concave grooves 38 and 38c are provided on both side surfaces of the side plate portion 32i constituting the pair of bushes 30i. For this reason, the resistance at the time of adjusting the vertical position of the steering wheel 1 (see FIG. 25) can be more stably suppressed to a low level. Other configurations and operations are the same as those in the fifth and sixth examples of the embodiment.

[Eighth Example of Embodiment]
12 to 14 show an eighth example of the embodiment of the present invention. In the case of this example, the bush 30j has the discontinuous part 40 which is a thinning part at one place in the circumferential direction. In this portion, the discontinuous portion 40 penetrates the cylindrical portion 31b in the thickness direction (the radial direction of the bush 30j) and penetrates the side plate portion 32j in the thickness direction (the axial direction of the bush 30j). Therefore, the bush 30j has a partially annular shape that is discontinuous in the circumferential direction at this portion. The width dimension of the discontinuous portion 40 in the circumferential direction is constant with respect to the axial direction of the cylindrical portion 31b at the portion corresponding to the cylindrical portion 31b and with respect to the radial direction of the side plate portion 32j at the portion corresponding to the side plate portion 32j. .

  In the case of this example, in order to secure the supporting ability of the anti-assist force by the bush 30j, even when the axial length of the cylindrical portion 31b and the radial height of the side plate portion 32j are sufficiently secured, the circumference The area of each contact portion that may cause a directional slip can be suppressed by the opening area of the discontinuous portion 40 in the contact portion. Therefore, even when any of the contact portions slips in the circumferential direction, the contact portion acts as a resistance when adjusting the height position of the steering wheel 1 (see FIG. 25). The frictional force can be stably kept low. Therefore, the workability when adjusting the height position of the steering wheel 1 can be improved.

  Further, even when the outer plate side of the side plate portion 32c is strongly compressed due to the deformation of the support plate portion 23, the outer diameter end portion of the side plate portion 32c is supported by the thinning portion provided on the side plate portion 32c. Accordingly, the side plate portion 32c can be prevented from abnormal wear. Therefore, it is possible to suppress the sag of the side plate portion 32c due to the repeated load of the assist reaction force, sufficiently ensure the durability of the side plate portion 32c, and prevent the occurrence of rattling in the tilt pivot portion for a long period of time. .

  In this example as well, grease can be applied to the surface of the bush 30j to reduce the frictional force acting on the contact portion between the surface of the bush 30j and the mating surface. In this case, the inside of the discontinuous portion 40 that is the thinning portion can be used as a grease reservoir. Other configurations and operations are the same as those of the first example, the fifth example, and the first example of the conventional structure of the embodiment of the present invention. Moreover, the structure of this example can be additionally applied to the structures of the first to seventh examples of the embodiment of the present invention.

[Ninth Embodiment]
FIG. 15 shows a ninth example of the embodiment of the invention. In the case of this example, the bush 30k has the discontinuous part 40 at one place in the circumferential direction, as in the case of the eighth example of the embodiment. Further, in the case of the bush 30k of the present example, among the side plate portions 32k, including the locations where the discontinuous portions 40 are present, the locations other than the locations where the discontinuous portions 40 are present among the four circumferentially spaced intervals. These three locations are also provided with discontinuous portions 40a, which are thinning portions. However, these discontinuous portions 40a are discontinuous portions only for the side plate portions 32k, and the cylindrical portion 31b is continuous.

  In the case of this example using such a bush 30k, compared to the case of the eighth example of the embodiment, the contact area between the both side surfaces of the side plate portion 32k and the mating surface is set as a discontinuous portion on these both side surfaces. This can be further reduced by the opening area of 40a. For this reason, the resistance at the time of adjusting the height position of the steering wheel 1 (refer FIG. 25) can be suppressed more stably and low. Other configurations and operations are the same as those in the eighth example of the embodiment.

[Tenth Example and Eleventh Example of Embodiment]
FIG. 16 shows a tenth example of the embodiment of the present invention, and FIG. 17 shows an eleventh example of the embodiment of the present invention. In the bushes 30m and 30n incorporated in the tenth and eleventh examples of these embodiments, the side plate portions 32m and 32n are arranged at a plurality of positions at equal intervals in the circumferential direction (three in the case of FIG. 16, FIG. 17). In this case, notches 41 and 41a are provided in the outer peripheral edges of the side plate portions 32m and 32n, each of which is a thinning portion.

  Also in the case of the tenth and eleventh examples of the embodiment of the present invention, the contact area between both side surfaces of the side plate portions 32m and 32n and the opposing surface facing these both side surfaces is represented by notches 41 on these both side surfaces. It can be suppressed by the opening area 41a. Other configurations and operations are the same as those in the eighth example of the embodiment.

[Twelfth and thirteenth embodiments]
18 shows a twelfth example of the embodiment of the present invention, and FIG. 19 shows a thirteenth example of the embodiment of the present invention. The bushes 30o and 30p of the twelfth example and the thirteenth example of these embodiments have a plurality of circumferentially equidistant locations (see FIG. 18) of continuous portions of the cylindrical portions 31c and 31d and the side plate portions 32o and 32p, respectively. In this case, three holes are provided, and four holes in the case of FIG. The through hole 42 penetrates the cylindrical portion 31c in the thickness direction (radial direction) and penetrates the side plate portion 32o in the thickness direction (axial direction). The through hole 42a penetrates the cylindrical portion 31d in the thickness direction and penetrates the side plate portion 32p in the thickness direction.

  In the twelfth example and the thirteenth example of the embodiment of the present invention, the contact area between both side surfaces of the side plate portions 32o and 32p and the mating surface, and both the inner and outer peripheral surfaces of the cylindrical portions 31c and 31d and the mating surface Can be suppressed by the opening area of the through holes 42 and 42a, respectively. Other configurations and operations are the same as those in the eighth example of the embodiment.

[Fourteenth and fifteenth embodiments]
FIG. 20 shows a fourteenth example of the embodiment of the present invention, and FIG. 21 shows a fifteenth example of the embodiment of the present invention. The bushes 30q and 30r of the fourteenth example and the fifteenth example of these embodiments are provided with a plurality of cutouts 41 or 41a similar to those in the tenth example or the eleventh example of the embodiment, respectively. A plurality of through holes 42 or 42a similar to those in the twelfth example or the thirteenth example are alternately arranged at equal intervals in the circumferential direction.

  According to the 14th example and the 15th example of the embodiment of the present invention, compared with the cases of the 10th to 13th examples, the resistance when adjusting the height position of the steering wheel 1 (see FIG. 25) is reduced. , More stable and low. Other configurations and operations are the same as those in the tenth or eleventh example of the embodiment and the twelfth or thirteenth example of the embodiment.

[Sixteenth and Seventeenth Examples of Embodiment]
FIG. 22 shows a sixteenth example of the embodiment of the present invention, and FIG. 23 shows a seventeenth example of the embodiment of the present invention. The bushes 30s and 30t of the sixteenth example and the seventeenth example of these embodiments each have a through hole 42 at one location in the circumferential direction of the bush 30q of the fourteenth example of the embodiment or the bush 30r of the fifteenth example. , 42a is provided with a discontinuous portion 40b which is a thinned portion.

  In the sixteenth and seventeenth examples of the embodiment of the present invention, compared to the fourteenth and fifteenth examples of the embodiment, the bushes 30s and 30t are provided by the discontinuous portion 40b. The contact area between the surface and the mating surface can be suppressed. For this reason, the resistance at the time of adjusting the height position of the steering wheel 1 (refer FIG. 25) can be suppressed more stably and low. Other configurations and operations are the same as those of the fourteenth example or the fifteenth example of the embodiment.

  Note that FIG. 24 is out of the technical scope of the present invention, but as with the present invention, the height of the steering wheel 1 (see FIG. 25) is secured while ensuring the support capability of the counter-assist force by the pair of bushes. When adjusting the position, a structure is shown in which the frictional force acting between the surface of the bush and the mating surface opposite to the surface can be stably kept low. In the case of this structure, the radial height of the side plate portion 32u constituting the bush 30u is lowered, and the ridge portion 43 protruding from the radial intermediate portion of the side surface of the swing bracket 28a is used as the outer diameter of the side plate portion 32u. In the neutral state, the distal end surface of the protrusion 43 is placed close to and opposed to the inner surface of the support plate 23. In the case of the structure shown in FIG. 24, the contact area between both side surfaces of the side plate portion 32u and the mating surface is reduced by the amount corresponding to the reduction in the radial height of the side plate portion 32u, The frictional force acting on the contact portion can be kept low. For this reason, the resistance at the time of adjusting the height position of the steering wheel 1 can be suppressed by that much. Further, when the swinging bracket 28a tends to be displaced and inclined in the axial direction due to the assist reaction force, the tip surface of the ridge portion 43 abuts against the inner surface of the support plate portion 23. Such displacement and tilt are prevented from becoming larger. In addition, a buffering action based on elastic deformation of the bush 30u can be obtained until the tip surface of the ridge 43 contacts the inner surface of the support plate 23.

DESCRIPTION OF SYMBOLS 1 Steering wheel 2, 2a Steering shaft 3, 3a Steering column 4, 4a Electric assist device 5 Tie rod 6 Steering gear unit 7 Inner shaft 8, 8a Outer shaft 9, 9a Inner column 10, 10a Outer column 11, 11a Housing 12, 12a Output shaft 13, 13a Front support bracket 14 Car body 15, 15a Tilt pivot shaft 16, 16a Rear support bracket 17 Adjusting handle 18 Universal joint 19 Intermediate shaft 20 Universal joint 21 Input shaft 22, 22a Electric motor 23 Support plate portion 24 Tilt bolt 25 Sleeve 26 Circular hole 27 Nut 28, 28a Oscillation bracket 29 Insertion hole 30, 30a-30k, 30m-30u Bush 31, 31a-31d Cylindrical part 32, 32a-3 k, 32m to 32u Side plate portion 33 Clearance 34a, 34b Clearance 35, 35a Step portion 36, 36a Main contact surface portion 37, 37a-37c Sub contact surface portion 38, 38a-38c Concave groove 39 Recess 40, 40a, 40b Discontinuous portion 41 , 41a Notch 42, 42a Through-hole 43 Projection

  The present invention relates to an electric power steering apparatus having a tilt mechanism capable of adjusting the height position of a steering wheel, and more particularly to a steering column support apparatus for swingably supporting the steering column on the vehicle body side.

  Automobile steering devices usually incorporate a tilt mechanism that allows the height position of the steering wheel to be adjusted according to the physique and driving posture of the driver, and a telescopic mechanism that allows the front and rear position of the steering wheel to be adjusted. ing. In addition, it is widely practiced to incorporate an electric power steering apparatus that uses an electric motor as a power source so that a driver can reduce the force of operating a steering wheel. FIG. 25 shows a conventional example of an electric power steering apparatus including a tilt mechanism and a telescopic mechanism.

  The steering device includes a steering shaft 2 that fixes a steering wheel 1 at a rear end portion, a steering column 3 that rotatably supports the steering shaft 2 on its inner diameter side, and an electric assist for applying auxiliary torque to the steering shaft 2. A device 4 and a steering gear unit 6 for pushing and pulling a pair of left and right tie rods 5 based on the rotation of the steering shaft 2 are provided. In addition, the front-back direction in this specification means the front-back direction of a vehicle body.

  In the electric power steering apparatus, the steering shaft 2 can transmit a rotational force and can be axially displaced relative to the inner shaft 7 disposed on the front side and the outer shaft 8 disposed on the rear side. By combining the two, the structure can be expanded and contracted in the axial direction. Further, the steering column 3 has a structure capable of extending and contracting in the axial direction by combining the inner column 9 disposed on the front side and the outer column 10 disposed on the rear side so as to allow relative displacement in the axial direction. It has become. The outer shaft 8 is rotatably supported inside the outer column 10 in a state where axial displacement with respect to the outer column 10 is suppressed.

  A front end portion of the inner column 9 is coupled and fixed to a rear end surface of the housing 11 constituting the electric assist device 4. On the other hand, the inner shaft 7 is inserted into the housing 11, and a front end portion thereof is coupled to an input shaft constituting the electric assist device 4. Further, the front end portion of the output shaft 12 constituting the electric assist device 4 connected to the input shaft via a torsion bar protrudes from the front end surface of the housing 11, so that the universal joint 18, the intermediate shaft 19, and another universal shaft are provided. The joint 20 is connected to the input shaft 21 of the steering gear unit 6 via the joint 20.

  The inner column 9 is supported by a part of the vehicle body 14 via the housing 11 by the front support bracket 13. In order to realize the tilt mechanism, the front support bracket 13 swings the housing 11 around the tilt pivot shaft 15 supported by the front support bracket 13 and extending in the width direction of the vehicle body 14 (front and back in FIG. 25). Support movably.

  An intermediate portion of the outer column 10 is supported by a part of the vehicle body 14 by a rear support bracket 16. In order to realize the tilt mechanism and the telescopic mechanism, the outer column 10 has a fixed state in which the rear support bracket 16 cannot be moved back and forth and moved up and down, and a non-fixed state in which the back and forth movement and vertical movement are enabled. Supported to be switchable. Regarding such a support structure, various structures have been conventionally known and are not a feature of the present invention, and thus detailed description thereof will be omitted.

  In the case of such an electric power steering device, when adjusting the height position and the front-rear position of the steering wheel 1, the adjustment handle 17 (see FIG. 26) is rotated in a predetermined direction (usually downward). The intermediate portion of the outer column 10 is set in an unfixed state with respect to the rear support bracket 16. In this state, the height position of the steering wheel 1 is adjusted by swinging the steering column 3 about the tilt pivot shaft 15. Further, the front / rear position of the steering wheel 1 is adjusted by extending / contracting the steering column 3 and the steering shaft 2. After the adjustment, the adjustment handle 17 is rotated in the direction opposite to the predetermined direction (usually upward), thereby fixing the intermediate portion of the outer column 10 with respect to the rear support bracket 16.

  Further, when torque is applied from the steering wheel 1 to the steering shaft 2 during steering, the electric assist device 4 detects the direction and magnitude of this torque with a torque sensor provided in the housing 11, and detects the detected torque. Accordingly, the electric motor 22 supported on the outer surface of the housing 11 is configured to apply an auxiliary torque (assist force) to the output shaft 12 via a worm-type speed reducer provided in the housing 11. .

  In the electric power steering apparatus provided with such a position adjustment mechanism of the steering wheel 1, as described in Japanese Patent No. 3707252, the tilt pivot portion, which is the swing center portion of the steering column 3, is provided. The durability of this tilt pivot portion is improved by assembling the bush to the sliding portion. 26 to 31 show a first example of a conventional structure of a steering column support device for an electric power steering device in which a bush is assembled to a tilt pivot portion.

  The front support bracket 13a is made of a metal plate such as a steel plate, and is spaced apart in the width direction of the vehicle body 14 (the front and back directions in FIGS. 26 and 30 and the left and right directions in FIGS. 27, 28, and 29). It has a pair of support plate parts 23 parallel to each other. Further, the tilt pivot shaft 15 a is disposed in the width direction of the vehicle body 14 in a state of being spanned between portions near the lower ends of the pair of support plate portions 23. The tilt pivot shaft 15a includes a tilt bolt 24 made of a metal material such as steel, and a cylindrical sleeve 25 made of a metal material such as steel or aluminum alloy. The tilt bolt 24 is inserted into a pair of circular holes 26 provided concentrically with each other at the lower end portion of the pair of support plate portions 23, and is connected to a male screw portion provided at the distal end portion of the flange portion. The nut 27 is screwed and further tightened, so that the nut 27 is attached between the support plate portions 23. In addition, the sleeve 25 is clamped and fixed between the support plate portions 23 based on the tightening of the nut 27 in a state where the sleeve 25 is externally fitted to the flange portion of the tilt bolt 24.

  The housing 11a constituting the electric assist device 4a is made of a metal material such as an aluminum alloy, and a swing bracket 28 is integrally provided at a front end portion thereof. An insertion hole 29 is provided in the width direction of the vehicle body 14 at the tip of the swing bracket 28. The inner peripheral surface of the insertion hole 29 is configured by a stepped cylindrical surface in which the inner diameter dimension at both axial end portions is slightly larger than the inner diameter dimension at the axial intermediate portion. The axial end portions and the axial intermediate portion of the stepped cylindrical surface are concentric with each other. With the front end portion or intermediate portion of the swing bracket 28 being disposed between the support plate portions 23, the swing bracket 28 is inserted into the support plate via the tilt bolt 24 and the sleeve 25 that pass through the insertion hole 29. By being supported between the portions 23, the housing 11a and the steering column 3a are supported with respect to the front support bracket 13a so as to be able to swing around the tilt pivot shaft 15a.

  A pair of bushes 30 are externally fitted to both axial ends of the sleeve 25 constituting the tilt pivot shaft 15a. Each bush 30 is formed in a circular tube shape as a whole by an elastic material including a synthetic resin such as polyamide resin and an elastomer such as rubber or vinyl, or a low friction material such as an oil-containing metal. And an annular (outward flange-like) side plate portion 32 extending radially outward from one axial end of the cylindrical portion 31. The cylindrical portion 31 of the bush 30 is sandwiched between the axial end portions of the outer peripheral surface of the sleeve 25 and the axial end portions of the inner peripheral surface of the insertion hole 29 so that there is no rattling in the radial direction. Is done. The side plate portions 32 of the bush 30 are sandwiched between both side surfaces in the width direction of the swing bracket 28 and the inner side surface of the support plate portion 23 so that there is no backlash in the axial direction.

  In the case of such a conventional structure, since the bush 30 is assembled to both ends in the axial direction of the tilt pivot shaft 15a, the swing bracket 28 is centered on the tilt pivot shaft 15a when the height position of the steering wheel 1 is adjusted. The tilt pivot shaft 15a and the swing bracket 28 are not directly rubbed with each other, but the support plate portion 23 and the swing bracket 28 are also prevented from being rubbed directly. Therefore, it is possible to avoid a situation in which a gap that causes rattling is generated in the tilt pivot portion constituted by these members due to wear and plastic deformation that are caused by direct friction between these members.

  In the case of the electric power steering device, when the electric assist device 4a applies assist force to the output shaft 12a, the assist reaction force, which is the reaction force, is opposite to the rotation direction of the output shaft 12a with respect to the housing 11a. Join. As a result, the swing bracket 28 constituting the housing 11a receives an assist reaction force against the tilt pivot shaft 15a and the support plate portion 23, and tends to be displaced and inclined in a direction opposite to the rotation direction of the output shaft 12a. Become. At this time, the bush 30 supports the assist reaction force while being elastically compressed between the tilt pivot shaft 15a and the support plate portion 23 and the swing bracket 28 or being pressed in the compression direction. The displacement and inclination of the swing bracket 28 are suppressed. This prevents the swing bracket 28, the tilt pivot shaft 15a and the support plate portion 23 from rubbing directly.

  By the way, in the case of the first example of the conventional structure, the axial length of the cylindrical portion 31 is ensured in order to ensure the supporting ability of the anti-assist force by the bush 30, that is, the ability to suppress the displacement and inclination of the swing bracket 28. And the radial direction height of the side-plate part 32 is enlarged to some extent, respectively. Further, the inner side surface of the support plate portion 23 and both side surfaces of the swing bracket 28 and both side surfaces of the side plate portion 32 are all parallel planes. For this reason, in a neutral state where no assist force is generated, both side surfaces of the side plate portion 32, the inner side surface of the support plate portion 23, and both side surfaces of the swing bracket 28 are in contact with each other almost entirely. Therefore, both the inner and outer peripheral surfaces of the cylindrical portion 31 and the mating surface (the outer peripheral surface of the tilt pivot shaft 15a or the vibration) are increased by the amount of the axial length of the cylindrical portion 31 and the radial height of the side plate portion 32. The contact area with the inner peripheral surface of the insertion hole 29 of the moving bracket 28 and the contact between both side surfaces of the side plate portion 32 and the mating surface (the inner surface of the support plate portion 23 or both side surfaces of the swinging bracket 28). Each area is larger.

  On the other hand, in the case of the first example of the conventional structure, when the height position of the steering wheel 1 is adjusted, the swing bracket 28 swings about the tilt pivot shaft 15a, so that the cylinder constituting the bush 30 is formed. At the contact portion between at least one surface of the inner peripheral surface of the portion 31 and the outer surface of the side plate portion 32, and the outer peripheral surface of the cylindrical portion 31 and the inner surface of the side plate portion 32, and the mating surface facing this surface , Slipping in the circumferential direction occurs. Since the frictional force acting on the contact portion becomes resistance when adjusting the height position of the steering wheel 1, it is desirable that the frictional force be as low and stable as possible. However, since the contact area between the inner and outer peripheral surfaces of the cylindrical portion 31 and both side surfaces of the side plate portion 32 and the mating surface is increased, the frictional force acting on the contact portion between the surface of the bush 30 and the mating surface is increased. Under the influence of the properties of these mating surfaces, it becomes relatively high and unstable, and there is a possibility that the feeling of operation when adjusting the height position of the steering wheel 1 is deteriorated.

  On the other hand, FIGS. 32A and 32B show the second and third examples of the conventional structure of the steering column support device for the electric power steering device described in Japanese Patent Laid-Open No. 2008-30728. Is shown. In these structures, the inner peripheral surface of the insertion hole 29a formed in the swing bracket 28a is away from the outer peripheral surface of the cylindrical portion 31a constituting the bush 30a (30b) as it goes from the central portion in the axial direction to both ends. It is inclined to. As a result, substantially cylindrical gaps 33 each having a wedge-shaped cross section are provided on both sides of the axially central portion between the inner peripheral surface of the insertion hole 29a and the outer peripheral surface of the cylindrical portion 31a. . In the case of the second example of the conventional structure shown in FIG. 32A, the outer surface of the side plate portion 32a constituting the bush 30a is away from the inner surface of the support plate portion 23 as it goes radially outward. It is inclined to. Thus, a substantially annular gap 34 a having a wedge-shaped cross section is provided between the outer side surface of the side plate portion 32 a and the inner side surface of the support plate portion 23. On the other hand, in the case of the third example of the conventional structure shown in FIG. 32B, the direction in which the inner side surface of the side plate portion 32b constituting the bush 30b moves away from the outer side surface of the swinging bracket 28a as it goes radially outward. It is inclined to. Thus, a substantially annular gap 34b having a wedge-shaped cross section is provided between the inner surface of the side plate portion 32a and the outer surface of the swing bracket 28a. Based on the presence of the gaps 33, 34a, 34b thus provided, the swing bracket 28a (the central axis of the insertion hole 29a) is easily inclined with respect to the central axis of the tilt pivot shaft 15a.

  Due to the shape error of the front support bracket 13a and the rear support bracket 16a, the mounting error with respect to the vehicle body 14 (see FIG. 26), etc., the middle of the steering column 3a (see FIG. 26) by the rear support bracket 16a during the tilting operation. The guide direction of the part may be inclined with respect to a virtual plane orthogonal to the central axis of the tilt pivot shaft 15a. In the second and third examples of the conventional structure, even in such a case, the swinging bracket 28a is inclined with respect to the central axis of the tilt pivot shaft 15a. The swinging direction of the steering column 3a at the time of adjustment and the guide direction of the intermediate portion of the steering column 3a are in agreement with each other. Therefore, it is possible to avoid a situation in which the adjustment operation of the height position of the steering wheel 1 becomes poor due to the mismatch between the swing direction and the guide direction.

  Further, in the case of the second and third examples of the conventional structure, the contact area between the inner peripheral surface of the insertion hole 29a and the outer peripheral surface of the cylindrical portion 31a is small based on the presence of the gap 33. For this reason, the frictional force which acts between the internal peripheral surface of the through-hole 29a and the outer peripheral surface of the cylindrical part 31a can be made small. Further, based on the presence of the gaps 34a and 34b, in the second example of the conventional structure, the contact surface pressure between the both side surfaces of the swing bracket 28a and the inner surfaces of the side plate portions 32a and 32b (see FIG. 32A). In the third example of the conventional structure, these contact areas (see FIG. 32B) can be reduced. Therefore, the frictional force acting between them can be stably reduced, and the height position of the steering wheel 1 can be adjusted by causing slippage between the swing bracket 28a and the bushes 30a, 30b. It is possible to improve the workability of the height position adjustment by keeping the resistance when performing the operation low.

  However, in the second and third examples of the conventional structure, the support rigidity of the swing bracket 28a by the tilt pivot shaft 15a is reduced based on the presence of the gap 33, and the steering wheel 1 (see FIG. 25) is reduced. Support rigidity is also lowered. As a result, the driver may feel uncomfortable. Further, due to the assist reaction force generated at the time of steering, the swing bracket 28a is relatively inclined with respect to the central axis of the tilt pivot shaft 15a based on the presence of the clearance 33 among the clearances 33, 34a, 34b. To do. This may also cause the driver to feel uncomfortable.

Japanese Patent No. 3707252 JP 2008-30728 A

  In view of the circumstances as described above, the present invention secures the supporting ability of the anti-assist force by the pair of bushes, and adjusts the height position of the steering wheel, and the surfaces of these bushes. An object of the present invention is to realize a structure of a steering column support device for an electric power steering device that can stably suppress the frictional force acting between the opposite surface and the opposite surface.

  The steering column support device of the present invention is particularly applied to an electric power steering device provided with a tilt mechanism. The steering column support device of the present invention includes a front support bracket, a tilt pivot shaft, a swing bracket, and a pair of bushes.

  The front support bracket includes a pair of support plate portions that are fixed to the vehicle body and arranged in parallel to each other in the width direction of the vehicle body. The tilt pivot shaft is disposed in the width direction of the vehicle body in a state of being spanned between the support plate portions. Further, the swing bracket is provided in a part of the housing of the electric assist device, has an insertion hole through which the tilt pivot shaft is inserted, and supports a steering column that rotatably supports the steering shaft via the housing. To do.

The pair of bushes are made of an elastic material or a low friction material, and are entirely formed in an annular shape. The bushes are respectively fitted on both ends in the axial direction of the tilt pivot shaft, and each is a cylinder sandwiched between the outer peripheral surface of the tilt pivot shaft and the inner peripheral surface of the insertion hole. And an annular side plate portion that extends radially outward from one axial end portion of the cylindrical portion and is sandwiched between a side surface of the swing bracket and an inner side surface of the support plate portion .

In particular, in the case of the steering column support device of the present invention, in each of the bushes, an assist force applied to the steering shaft by at least the electric assist device is generated on the inner diameter side half of the inner surface of the side plate portion. is primarily contact surface in contact with the side surface of the swing bracket in a neutral state no formation, the outer diameter side half of the inner surface of the side plate portion, at least in the neutral state, contacts the side surface of the swing bracket Instead, only when the side plate portion is elastically deformed by the reaction force of the assist force, a sub-contact surface portion that forms a recess that contacts the side surface of the swing bracket is formed. When the swing bracket swings about the tilt pivot shaft in the neutral state, the side surface of the swing bracket and the inner side surface of the side plate portion slide.

  In the steering column support device of the present invention, the diameter of the portion of the outer peripheral surface of the tilt pivot shaft and the inner peripheral surface of the insertion hole that holds the cylindrical portion of the bush does not change in the axial direction. It is preferable that each cylindrical portion of the bush is supported as a cylindrical surface without rattling between the outer peripheral surface of the tilt pivot shaft and the inner peripheral surface of the insertion hole.

According to the steering column support device of the present invention, even when the supporting ability of the counter-assist force by the pair of bushes is ensured, when the height position of the steering wheel is adjusted , the side surfaces of the side plates of the bushes are shaken. The frictional force acting between the side surfaces of the moving bracket can be stably kept low. That is, a sub-contact surface portion that constitutes a recess that is in a non-contact state with the side surface of the swinging bracket in a neutral state where at least assist force is not generated, is provided on the outer-diameter half of the inner surface of the side plate portion that constitutes the bush. Provided. Therefore, by reducing the contact area between the inner surface and the side surface of the swing bracket side plate portion of the bush by the amount of the secondary contact surface, the resistance when adjusting the height position of the steering wheel, the side plates of the bushing The frictional force acting on the contact portion between the inner side surface of the portion and the side surface of the swing bracket is stably kept low, thereby improving the workability of the adjustment operation of the height position of the steering wheel.

FIG. 1 is an enlarged view showing a tilt pivot portion of a first example of a reference example related to the present invention in a cut state. FIG. 2 is an enlarged view of part a in FIG. FIG. 3 is a view similar to FIG. 2, showing a first example of an embodiment of the present invention. FIG. 4 is a view similar to FIG. 2, showing a second example of a reference example related to the present invention . FIG. 5 is a view similar to FIG. 2, showing a second example of the embodiment of the present invention. FIG. 6 is a view similar to FIG. 28, showing a third example of the reference example related to the present invention . FIG. 7 is an enlarged view of part b of FIG. FIG. 8 is a view of the bush incorporated in the third example of the reference example related to the present invention as seen from the outer surface side of the side plate portion. FIGS. 9A to 9C are views showing three examples of the concave portions provided on the side surface of the side plate portion, which can be incorporated into the third example of the reference example related to the present invention . FIG. 10 is a view similar to FIG. 7, showing a fourth example of the reference example related to the present invention . FIG. 11 is a view similar to FIG. 7, showing a fifth example of the reference example related to the present invention . FIG. 12 is a view similar to FIG. 1, showing a sixth example of the reference example related to the present invention . 13 is a cross-sectional view taken along the line cc of FIG. FIG. 14 (A) is a side view of a bush incorporated in a sixth example of a reference example related to the present invention , and FIG. 14 (B) is a view seen from the right side of FIG. 14 (A). 15A is a cross-sectional view (a cross-sectional view taken along the line dd in FIG. 15B) of the bush incorporated in the seventh example of the reference example related to the present invention , and FIG. 15B is a cross-sectional view of FIG. It is the figure seen from the right side. FIG. 16 is a view similar to FIG. 14 showing a bush incorporated in the eighth example of the reference example related to the present invention . FIG. 17 is a view similar to FIG. 14 showing a bush incorporated in the ninth example of the reference example related to the present invention . FIG. 18 is a view similar to FIG. 14 showing a bush incorporated in a tenth reference example related to the present invention . FIG. 19 is a view similar to FIG. 14 showing a bush incorporated in an eleventh reference example related to the present invention . FIG. 20 is a view similar to FIG. 14 showing the bush incorporated in the twelfth example of the reference example related to the present invention . FIG. 21 is a view similar to FIG. 14 showing a bush incorporated in a thirteenth reference example related to the present invention . FIG. 22 is a view similar to FIG. 14 showing a bush incorporated in a fourteenth example of a reference example related to the present invention . FIG. 23 is a view similar to FIG. 14 showing a bush incorporated in the fifteenth example of the reference example related to the present invention . FIG. 24 shows a structure reference in which the force required to adjust the height position of the steering wheel can be reduced, and the amount by which the swing bracket tilts with respect to the center axis of the tilt pivot shaft can be suppressed by the assist reaction force. It is a figure similar to FIG. 2 which shows an example. FIG. 25 is a schematic side view showing an example of a conventional structure of an electric power steering apparatus provided with a tilt mechanism in a state where a part thereof is cut. FIG. 26 is a side view of an essential part showing a first example of a conventional structure of a steering column support device. FIG. 27 is a view from the left of FIG. 26, showing the tilt pivot portion in a cut state. FIG. 28 is an enlarged view of part e in FIG. FIG. 29 is an enlarged view of part f in FIG. 30 is a cross-sectional view taken along the line gg of FIG. FIG. 31 is a view similar to FIG. 14 showing the bush incorporated in the first example of the conventional structure. FIG. 32 (A) is a view similar to FIG. 29 showing a bush incorporated in the second example of the conventional structure of the steering column support device, and FIG. 32 (B) is a third view of the conventional structure of the steering column support device. It is a figure similar to FIG. 29 which shows the bush integrated in an example.

[ First example of reference example ]
1 to 2 show a first example of a reference example related to the present invention . The steering column support device of the present invention is particularly applied to an electric power steering device provided with a tilt mechanism. The steering column support device of the present invention includes a front support bracket 13a, a tilt pivot shaft 15a, a swing bracket 28, and a pair of bushes 30c. The front support bracket 13a has a pair of support plate portions 23 that are fixed to the vehicle body and arranged in parallel with each other in the width direction of the vehicle body. The tilt pivot shaft 15a is disposed in the width direction of the vehicle body in a state of being spanned between the support plate portions 23. The swing bracket 28 is provided in a part of the housing of the electric assist device, and has an insertion hole 29 through which the tilt pivot shaft 15a is inserted. Each bush 30c is made of an elastic material including a synthetic resin such as a polyamide resin and an elastomer such as rubber or vinyl or a low friction material such as an oil-impregnated metal. A cylindrical portion 31 that is externally fitted to both axial ends of the pivot shaft 15a and is sandwiched between the outer peripheral surface of the tilt pivot shaft 15a and the inner peripheral surface of the insertion hole 29; The ring-shaped side plate portion 32c extends radially outward from one end portion in the axial direction and is sandwiched between the side surface of the swing bracket 28 and the inner surface of the support plate portion 23. The feature of this reference example is the structure of the outer surface of the side plate portion 32c of each bush 30c and the installation location of the cylindrical portion 31 of the bush 30c. The structure and operation of the other parts are the same as in the first example of the conventional structure.

In the case of this reference example , the inner side surface which opposes both the side surfaces of the swing bracket 28 among the both side surfaces of the side plate portion 32c of the bush 30c is a single ring surface. On the other hand, step portions 35 are formed on the inner peripheral portions of the outer surfaces facing the inner surfaces of the pair of support plate portions 23 constituting the front support bracket 13a among the both side surfaces of the side plate portion 32c. ing. As a result, the outer side surface of the side plate portion 32c is positioned on the inner side in the axial direction with respect to the inner side portion which is the other half portion of the radially opposite side portions sandwiching the step portion 35. It is a stepped ring with a stepped back. The inner diameter side portion of the both radial side portions sandwiching the step portion 35 is a single ring-shaped main contact surface portion 36, and the outer diameter side portion is concentric with the main contact surface portion 36 and has a single annular shape sub-portion. The contact surface portion 37 is used. Then, in the neutral state where the assist reaction force is not acting, as shown in FIGS. 1 and 2, almost the entire inner surface of the side plate portion 32 c is brought into contact with both side surfaces of the swing bracket 28. On the other hand, the outer side surface of the side plate portion 32 c makes only the main contact surface portion 36 of the radially inner portion contact the inner side surface of the support plate portion 23. That is, in this state, of the outer surface of the side plate portion 32c, the sub-contact surface portion 37 of the radially outer portion is not in contact with the inner side surface of the support plate portion 23, and with respect to the inner side surface of the support plate portion 23, It is opposed through a small gap.

  On the other hand, the cylindrical portion 31 constituting the bush 30c is a cylindrical surface whose diameter does not change with respect to the axial direction, both axial end portions of the outer peripheral surface of the sleeve 25 constituting the tilt pivot shaft 15a, and the swing bracket 28. The insertion hole 29 is sandwiched between both ends of the inner peripheral surface in the axial direction. That is, in the neutral state, as shown in FIGS. 1 to 2, almost the entire inner and outer peripheral surfaces of the cylindrical portion 31 (at least portions excluding the chamfered portions on both the radially inner and outer peripheral edges of both axial end portions) are the sleeves. In this state, both end portions of the outer peripheral surface of 25 and both end portions of the inner peripheral surface of the insertion hole 29 are in contact with no gap.

According to the steering column support device of the present reference example , the support rigidity of the swing bracket 28 by the tilt pivot shaft 15a can be sufficiently secured, and the swing bracket 28 is centered on the tilt pivot shaft 15a by the assist reaction force generated during steering. The amount of inclination with respect to the axis can be sufficiently suppressed. Moreover, the resistance at the time of adjusting the height position of the steering wheel 1 (see FIG. 25) can be kept low in a state where the durability of the side plate portion 32c constituting the bush 30c is sufficiently ensured.

That is, in the case of the present reference example , portions of the outer peripheral surface of the sleeve 25 that constitutes the tilt pivot shaft 15a and the inner peripheral surface of the insertion hole 29 that sandwich the cylindrical portion 31 that constitutes the bush 30c are respectively shafts. It is a cylindrical surface whose diameter does not change over the direction. And, in a neutral state, these cylindrical surfaces are respectively removed from the entire inner and outer peripheral surfaces of the cylindrical portion 31 (at least portions excluding the chamfered portions at both ends) except for a minute gap necessary for relative rotation, It is in contact with almost no gap. Therefore, the support rigidity of the swing bracket 28 by the tilt pivot shaft 15a can be sufficiently secured. Further, when the swing bracket 28 tends to be inclined with respect to the central axis of the tilt pivot shaft 15a due to the assist reaction force, the assist reaction force can be efficiently supported by the cylindrical portion 31. For this reason, this amount of inclination can be suppressed sufficiently low.

Further, in the case of this reference example , in the neutral state, which is also a state in which the height position of the steering wheel 1 is adjusted, the outer side surface of the side plate portion 32c constituting the bush 30c is in relation to the inner side surface of the support plate portion 23. Contact is made only at the main contact surface portion 36 and not at the sub contact surface portion 37. For this reason, in the neutral state, the contact area between the outer surface of the side plate portion 32c and the inner surface of the support plate portion 23 is reduced, and the frictional force acting on the contact portion between these outer surface and inner surface is reduced. Can do. Therefore, when the height position of the steering wheel 1 is adjusted, the resistance when adjusting the height position of the steering wheel 1 is reduced by sliding the outer surface of the side plate portion 32c and the inner surface of the support plate portion 23. It can be kept low.

In the case of this reference example , the swing bracket 28 is displaced toward one of the support plate portions 23 of the pair of support plate portions 23 by the assist reaction force, and the central axis of the tilt pivot shaft 15a. When at least a part of the side plate portion 32c in the circumferential direction is pushed by the both side surfaces of the swing bracket 28, it is elastically deformed. As a result, the outer surface of the elastically deformed portion of the side plate portion 32 c comes into contact with the inner surface of the support plate portion 23 not only at the main contact surface portion 36 but also at the sub contact surface portion 37. For this reason, with respect to the side plate portion 32 c, the assist reaction force can be supported in a wide range including not only a portion corresponding to the main contact surface portion 36 but also a portion corresponding to at least a part of the sub contact surface portion 37. Further, as the swing bracket 28 is displaced, the support plate 23 is deformed. Due to the deformation of the support plate portion 23, the outer diameter side of the side plate portion 32 c is more strongly compressed by the deformation of the support plate portion 23. However, in the case of the present reference example , since the relief by the sub-contact surface portion 37 is made in this portion, abnormal wear of the side plate portion 32c is prevented. Therefore, it is possible to suppress the sag of the side plate portion 32c due to the repeated load of the assist reaction force, sufficiently ensure the durability of the side plate portion 32c, and prevent the occurrence of rattling in the tilt pivot portion for a long period of time. .

[ First example of embodiment]
FIG. 3 shows a first example of the embodiment of the present invention. In the case of this example, with respect to each of the pair of bushes 30d, the configuration of both side surfaces of the side plate portion 32d is reversed from the case of the first example of the reference example . That is, in the case of this example, the outer side surface of the side plate portion 32d is a single ring surface, and the inner side surface of the side plate portion 32d is the main contact surface portion 36a on the inner diameter side and the sub contact surface portion 37a on the outer diameter side. It is set as the stepped ring surface which continued through the step part 35a. Then, in the neutral state where the assist reaction force is not acting, as shown in FIG. 3, the entire outer side surface of the side plate portion 32d is brought into contact with the inner side surface of the support plate portion 23, and the inner side surface of the side plate portion 32d is Of these, only the main contact surface portion 36 a is in contact with the side surface of the swing bracket 28. Also in the case of this example, based on the presence of the main contact surface portion 36a and the sub contact surface portion 37a, the same operational effects as those of the first example of the reference example can be achieved. The configuration and operation of the other parts are the same as in the first example of the reference example .

[ Second example of reference example ]
FIG. 4 shows a second example of a reference example related to the present invention . In the case of this reference example , regarding each of the pair of bushes 30e, the configuration of the sub-contact surface portion 37b provided on the outer diameter side portion of the outer side surface of the side plate portion 32e is different from that of the first example of the reference example. Yes. That is, in the case of this reference example , the inner peripheral edge of the sub-contact surface portion 37b is directly connected to the outer peripheral edge of the main contact surface portion 36 provided on the inner diameter side portion without a stepped portion. Further, the sub-contact surface portion 37b is an inclined surface that is inclined in a direction away from the inner surface of the support plate portion 23 as it goes outward in the radial direction. In the case of this reference example , the cross-sectional shape of the sub-contact surface portion 37b that is an inclined surface is a linear shape, but this cross-sectional shape is curved in a direction that is convex with respect to the inner side surface of the support plate portion 23. It can also be a curved shape.

In the case of this reference example, the main contact surface portion 36 provided on one side surface of the side plate portion 32e constituting the bush 30e is a flat surface parallel to the mating surface, and the sub-contact surface portion 37b is opposed to the outer surface in the radial direction. The inclined surface is inclined in a direction away from. However, the entire one side surface of the side plate portion is an inclined surface that inclines in a direction away from the mating surface as it goes outward in the radial direction, and the portion that contacts the mating surface in the neutral state is the main contact surface portion. The portion that does not come into contact with the mating surface can be used as the sub-contact surface portion. Other configurations and operations are the same as those in the first example of the reference example .

[ Second Example of Embodiment]
FIG. 5 shows a second example of the embodiment of the present invention. In the case of this example, the configuration of the sub-contact surface portion 37c provided on the outer diameter side portion of the inner surface of the side plate portion 32f is made different from that of the first example of the embodiment for each of the pair of bushes 30f. Yes. That is, in the case of this example, the inner peripheral edge of the sub-contact surface portion 37c is directly connected to the outer peripheral edge of the main contact surface portion 36a provided on the inner diameter side portion without a stepped portion. Further, the sub-contact surface portion 37c is an inclined surface that is inclined in a direction away from the side surface of the swing bracket 28 as it goes outward in the radial direction. Other configurations and operations are the same as those of the first example of the embodiment and the second example of the reference example .

[ Third example of reference example ]
6 to 8 show a third example of the reference example related to the present invention . In the case of this reference example , an annular concave groove 38 that is continuous over the entire circumference is provided concentrically with the side plate portion 32g in the radially intermediate portion of the outer side surface of both side surfaces of the side plate portion 32g constituting the bush 30g. Yes. Then, at least in a neutral state where the assist reaction force is not acting, only the portion of the outer surface of the side plate portion 32g that is out of the concave groove 38 is brought into contact with the inner surface of the support plate portion 23.

According to the steering column support device of the present reference example , in order to secure the supporting ability of the anti-assist force by the side plate portion 32g constituting the bush 30g, even when trying to ensure a sufficient radial height of the side plate portion 32g, In the neutral state, the contact area between the outer side surface of the side plate portion 32g and the inner side surface of the support plate portion 23 can be reduced by the opening area of the concave groove 38. For this reason, it acts on the contact portion between the outer side surface of the side plate portion 32g and the inner side surface of the support plate portion 23 in the neutral state, which becomes resistance when adjusting the height position of the steering wheel 1 (see FIG. 25). The frictional force can be stably reduced. Therefore, it is possible to avoid a situation in which the frictional force is large and unstable, and workability when the height position of the steering wheel 1 is adjusted is deteriorated.

  Further, even when the outer plate side of the side plate portion 32c is strongly compressed by the deformation of the support plate portion 23, the outer plate end portion of the side plate portion 32c is bent because the concave groove 38 is formed in the side plate portion 32c. It is easy to absorb the deformation of the side plate portion 32c, and abnormal wear of the side plate portion 32c is prevented. Therefore, it is possible to suppress the sag of the side plate portion 32c due to the repeated load of the assist reaction force, sufficiently ensure the durability of the side plate portion 32c, and prevent the occurrence of rattling in the tilt pivot portion for a long period of time. .

In the case of carrying out the present reference example , grease is applied to the surface of the bush 30g, and the surface of the bush 30g (both inner and outer peripheral surfaces of the cylindrical portion 31 and both side surfaces of the side plate portion 32g) and the counterpart facing this surface. The frictional force acting on the contact portions with the surfaces (the inner peripheral surface of the insertion hole 29 and the outer peripheral surface of the sleeve 25, and the inner surface of the support plate portion 23 and both side surfaces of the swing bracket 28) can also be reduced. In this case, since the concave groove 38 can be used as a grease reservoir, the amount of grease retained can be increased by that much, and the effect of reducing the frictional force can be retained for a long time. Moreover, the number of the annular concave grooves provided on the side surface of the side plate portion 32g can be plural. Furthermore, a plurality of annular grooves having different diameters can be arranged in an annual ring shape, preferably concentrically.

In addition, as a recessed part provided in the side surface of the side-plate part which comprises a bush, it is not restricted to the annular recessed groove 38 continued over the perimeter, About the circumferential direction as shown to FIG. 9 (A) and FIG. 9 (B). A plurality of arc-shaped concave grooves 38a that are long in the circumferential direction, a plurality of concave grooves 38b that are long in the radial direction, and are provided at regular intervals in the circumferential direction as shown in FIG. 9C. It is also possible to adopt a structure such as a round recess 39. Other configurations and operations are the same as those of the first example of the reference example and the first example of the conventional structure.

[ Fourth Reference Example ]
FIG. 10 shows a fourth example of the reference example related to the present invention . In the case of this reference example , an annular concave groove 38c that is continuous over the entire circumference at the radially intermediate portion of the inner side surface (side surface on the swing bracket 28 side) of the side plate portion 32h constituting the pair of bushes 30h. Is provided concentrically with the side plate portion 32h. In the neutral state in which no assist reaction force is generated, only the portion of the inner side surface of the side plate portion 32 h that is out of the concave groove 38 c is brought into contact with both side surfaces of the swing bracket 28.

Even in the case of the steering column support device of the present reference example , in order to secure the supporting ability of the counter-assist force by the side plate portion 32h constituting the bush 30h, the neutral state is maintained even when the radial height of the side plate portion 32h is sufficiently secured. Thus, the contact area between the inner side surface of the side plate portion 32h and both side surfaces of the swing bracket 28 can be suppressed by the opening area of the concave groove 38c. For this reason, it acts on the contact portion between the inner side surface of the side plate portion 32h and both side surfaces of the swinging bracket 28 in the neutral state, which becomes resistance when adjusting the height position of the steering wheel 1 (see FIG. 25). The frictional force can be stably reduced. Other configurations and operations are the same as those in the third example of the reference example .

[ Fifth Reference Example ]
FIG. 11 shows a fifth example of the reference example related to the present invention . In the case of the reference example , the concave grooves 38 and 38c are provided on both side surfaces of the side plate portion 32i constituting the pair of bushes 30i. For this reason, the resistance at the time of adjusting the vertical position of the steering wheel 1 (see FIG. 25) can be more stably suppressed to a low level. Other configurations and operations are the same as those in the third and fourth examples of the reference example .

[ Sixth example of reference example ]
12 to 14 show a sixth example of the reference example related to the present invention . In the case of this reference example , the bush 30j has the discontinuous part 40 which is a thinning part in one place of the circumferential direction. In this portion, the discontinuous portion 40 penetrates the cylindrical portion 31b in the thickness direction (the radial direction of the bush 30j) and penetrates the side plate portion 32j in the thickness direction (the axial direction of the bush 30j). Therefore, the bush 30j has a partially annular shape that is discontinuous in the circumferential direction at this portion. The width dimension of the discontinuous portion 40 in the circumferential direction is constant with respect to the axial direction of the cylindrical portion 31b at the portion corresponding to the cylindrical portion 31b and with respect to the radial direction of the side plate portion 32j at the portion corresponding to the side plate portion 32j. .

In the case of this reference example , in order to secure the supporting ability of the anti-assist force by the bush 30j, even when the axial length of the cylindrical portion 31b and the radial height of the side plate portion 32j are sufficiently secured, The area of each contact portion that may cause a slip in the circumferential direction can be suppressed by the opening area of the discontinuous portion 40 in the contact portion. Therefore, even when any of the contact portions slips in the circumferential direction, the contact portion acts as a resistance when adjusting the height position of the steering wheel 1 (see FIG. 25). The frictional force can be stably kept low. Therefore, the workability when adjusting the height position of the steering wheel 1 can be improved.

  Further, even when the outer plate side of the side plate portion 32c is strongly compressed due to the deformation of the support plate portion 23, the outer diameter end portion of the side plate portion 32c is supported by the thinning portion provided on the side plate portion 32c. Accordingly, the side plate portion 32c can be prevented from abnormal wear. Therefore, it is possible to suppress the sag of the side plate portion 32c due to the repeated load of the assist reaction force, sufficiently ensure the durability of the side plate portion 32c, and prevent the occurrence of rattling in the tilt pivot portion for a long period of time. .

In this reference example , grease can be applied to the surface of the bush 30j to reduce the frictional force acting on the contact portion between the surface of the bush 30j and the mating surface. In this case, the inside of the discontinuous portion 40 that is the thinning portion can be used as a grease reservoir. Other configurations and operations are the same as those of the first example of the reference example, the third example of the reference example, and the first example of the conventional structure. Further, the structure of this example can be additionally applied to the structures of the first to second examples of the embodiment of the present invention and the first to fifth examples of the reference example .

[ Seventh example of reference example ]
FIG. 15 shows a seventh example of the reference example related to the present invention . In the case of this reference example , the bush 30k has the discontinuous part 40 at one place in the circumferential direction as in the case of the sixth example of the reference example . Furthermore, in the case of the bush 30k of the present reference example , the location where the discontinuous portion 40 is present among the four circumferentially equidistant locations including the location where the discontinuous portion 40 exists in the side plate portion 32k. The discontinuous part 40a which is a thinning part is provided also in three places other than. However, these discontinuous portions 40a are discontinuous portions only for the side plate portions 32k, and the cylindrical portion 31b is continuous.

In the case of this reference example using such a bush 30k, compared with the case of the sixth example of the reference example, the contact area between both side surfaces of the side plate portion 32k and the mating surface is set as a discontinuous portion on these both side surfaces. This can be further reduced by the opening area of 40a. For this reason, the resistance at the time of adjusting the height position of the steering wheel 1 (refer FIG. 25) can be suppressed more stably and low. Other configurations and operations are the same as those of the sixth example of the reference example .

[ Eighth and ninth examples of reference examples ]
FIG. 16 shows an eighth example of the reference example related to the present invention, and FIG. 17 shows a ninth example of the reference example related to the present invention . The bushes 30m and 30n incorporated in the eighth example and the ninth example of the reference examples are respectively provided at a plurality of circumferentially equidistant positions of the side plate portions 32m and 32n (three in the case of FIG. 16 and FIG. 17). In this case, notches 41 and 41a are provided at the outer peripheral edges of the side plate portions 32m and 32n.

Also in the case of the eighth example and the ninth example of the reference example, the contact area between both side surfaces of the side plate portions 32m and 32n and the mating surface facing these both side surfaces is defined as the opening area of the notches 41 and 41a on these both side surfaces. It can be suppressed by the amount. Other configurations and operations are the same as those of the sixth example of the reference example .

[ 10th and 11th Reference Examples ]
18 shows a tenth example of a reference example related to the present invention, and FIG. 19 shows an eleventh example of a reference example related to the present invention . In the bushes 30o and 30p of the tenth example and the eleventh example of these reference examples, a plurality of circumferentially equidistant locations in the continuous portion of the cylindrical portions 31c and 31d and the side plate portions 32o and 32p (in the case of FIG. 18). Are provided with through-holes 42 and 42a which are thinning portions, respectively, at three places and four places in the case of FIG. The through hole 42 penetrates the cylindrical portion 31c in the thickness direction (radial direction) and penetrates the side plate portion 32o in the thickness direction (axial direction). The through hole 42a penetrates the cylindrical portion 31d in the thickness direction and penetrates the side plate portion 32p in the thickness direction.

Also in the case of the tenth example and the eleventh example of the reference example, the contact area between the both side surfaces of the side plate portions 32o and 32p and the mating surface, and the contact area between the inner and outer peripheral surfaces of the cylindrical portions 31c and 31d and the mating surface are determined. , Respectively, can be suppressed by the opening area of the through holes 42 and 42a. Other configurations and operations are the same as those of the sixth example of the reference example .

[ Twelfth and thirteenth reference examples ]
FIG. 20 shows a twelfth example of a reference example related to the present invention, and FIG. 21 shows a thirteenth example of a reference example related to the present invention . In the bushes 30q and 30r of the twelfth example and the thirteenth example of the reference examples, a plurality of notches 41 or 41a similar to those in the eighth example or the ninth example of the reference example and the tenth example of the reference example, respectively. A plurality of through holes 42 or 42a similar to those in the example or the eleventh example are alternately arranged at equal intervals in the circumferential direction.

According to the twelfth example and the thirteenth example of the reference example , compared with the cases of the eighth example to the eleventh example of the reference example, the resistance when adjusting the height position of the steering wheel 1 (see FIG. 25) More stable and low. Other configurations and operations are the same as those of the eighth or ninth example of the reference example and the tenth or eleventh example of the reference example .

[ 14th and 15th examples of reference examples ]
FIG. 22 shows a fourteenth example of a reference example related to the present invention, and FIG. 23 shows a fifteenth example of a reference example related to the present invention . The bushes 30s and 30t of the fourteenth and fifteenth examples of the reference examples each have through holes at one location in the circumferential direction of the bush 30q of the twelfth example of the reference example or the bush 30r of the thirteenth example of the reference example. Discontinuous portions 40b, which are thinning portions, are provided in portions that are out of 42 and 42a.

In the case of the 14th example and the 15th example of the reference example, the surfaces of the bushes 30s and 30t and the mating surface are provided by the amount of the discontinuous portion 40b compared to the cases of the 12th and 13th examples of the reference example. The contact area with can be suppressed. For this reason, the resistance at the time of adjusting the height position of the steering wheel 1 (refer FIG. 25) can be suppressed more stably and low. Other configurations and operations are the same as those in the twelfth or thirteenth example of the reference example .

  Note that FIG. 24 is out of the technical scope of the present invention, but as with the present invention, the height of the steering wheel 1 (see FIG. 25) is secured while ensuring the support capability of the counter-assist force by the pair of bushes. When adjusting the position, a structure is shown in which the frictional force acting between the surface of the bush and the mating surface opposite to the surface can be stably kept low. In the case of this structure, the radial height of the side plate portion 32u constituting the bush 30u is lowered, and the ridge portion 43 protruding from the radial intermediate portion of the side surface of the swing bracket 28a is used as the outer diameter of the side plate portion 32u. In the neutral state, the distal end surface of the protrusion 43 is placed close to and opposed to the inner surface of the support plate 23. In the case of the structure shown in FIG. 24, the contact area between both side surfaces of the side plate portion 32u and the mating surface is reduced by the amount corresponding to the reduction in the radial height of the side plate portion 32u, The frictional force acting on the contact portion can be kept low. For this reason, the resistance at the time of adjusting the height position of the steering wheel 1 can be suppressed by that much. Further, when the swinging bracket 28a tends to be displaced and inclined in the axial direction due to the assist reaction force, the tip surface of the ridge portion 43 abuts against the inner surface of the support plate portion 23. Such displacement and tilt are prevented from becoming larger. In addition, a buffering action based on elastic deformation of the bush 30u can be obtained until the tip surface of the ridge 43 contacts the inner surface of the support plate 23.

DESCRIPTION OF SYMBOLS 1 Steering wheel 2, 2a Steering shaft 3, 3a Steering column 4, 4a Electric assist device 5 Tie rod 6 Steering gear unit 7 Inner shaft 8, 8a Outer shaft 9, 9a Inner column 10, 10a Outer column 11, 11a Housing 12, 12a Output shaft 13, 13a Front support bracket 14 Car body 15, 15a Tilt pivot shaft 16, 16a Rear support bracket 17 Adjusting handle 18 Universal joint 19 Intermediate shaft 20 Universal joint 21 Input shaft 22, 22a Electric motor 23 Support plate portion 24 Tilt bolt 25 Sleeve 26 Circular hole 27 Nut 28, 28a Oscillation bracket 29 Insertion hole 30, 30a-30k, 30m-30u Bush 31, 31a-31d Cylindrical part 32, 32a-3 k, 32m to 32u Side plate portion 33 Clearance 34a, 34b Clearance 35, 35a Step portion 36, 36a Main contact surface portion 37, 37a-37c Sub contact surface portion 38, 38a-38c Concave groove 39 Recess 40, 40a, 40b Discontinuous portion 41 , 41a Notch 42, 42a Through-hole 43 Projection

Claims (13)

A front support bracket having a pair of support plate portions fixed to the vehicle body and spaced apart from each other in the width direction of the vehicle body;
A tilt pivot shaft disposed in a width direction of the vehicle body in a state of being spanned between the support plate portions;
A swing bracket provided in a part of a housing of the electric assist device, having an insertion hole through which the tilt pivot shaft is inserted, and supporting a steering column that rotatably supports a steering shaft via the housing;
It is made of an elastic material or a low-friction material, and is formed in an annular shape as a whole, and is fitted around both ends of the tilt pivot shaft in the axial direction, and each is inserted through the outer peripheral surface of the tilt pivot shaft and the insertion A cylindrical portion sandwiched between the inner peripheral surface of the hole, and extending radially outward from one axial end portion of the cylindrical portion, between the side surface of the swing bracket and the inner side surface of the support plate portion At least one of the two peripheral surfaces of the cylindrical portion in a neutral state where at least the assist force applied to the steering shaft is not generated by the electric assist device. A pair of bushes, wherein a part of the side plate or at least one of both side surfaces of the side plate portion is provided with a thinning portion that is not in contact with a mating surface facing these surfaces; ,
A steering column support device comprising:   2. The steering column support device according to claim 1, wherein the thinning portion is configured by a recess provided in at least one of both side surfaces of the side plate portion.   A main contact surface portion that is in contact with the mating surface in at least the neutral state is formed in at least one radial half of at least one of the both side surfaces of the side plate portion, and at least the neutral in the other half in the radial direction. In the state, a sub-contact surface portion that contacts the mating surface is formed only when the side plate portion is elastically deformed by the reaction force of the assist force without contacting the mating surface, and the sub-contact surface portion is formed into the concave portion. The steering column support device according to claim 2, comprising:   The steering column support device according to claim 3, wherein the main contact surface portion is provided on the inner diameter side, and the sub contact surface portion is provided on the outer diameter side.   The steering column support device according to claim 2, wherein the concave portion is provided in at least one radial intermediate portion of both side surfaces of the side plate portion.   The steering column support device according to claim 5, wherein the concave portion is provided with a plurality of circumferentially extending concave grooves provided at a plurality of positions in at least one of the both side surfaces of the side plate portion.   The steering column support device according to claim 5, wherein the concave portion is constituted by a concave groove extending in a circumferential direction of at least one of both side surfaces of the side plate portion.   The steering column support device according to claim 7, wherein the concave groove is formed over the entire circumference of at least one of both side surfaces of the side plate portion.   2. The steering column support device according to claim 1, wherein the thinning portion is formed so as to penetrate through the thickness direction in at least one circumferential direction of at least one of the cylindrical portion and the side plate portion. .   The said thinning part is comprised by the discontinuous part which makes a part of the circumferential direction discontinuous in at least one circumferential direction location of at least one of the said cylindrical part and the said side plate part. Steering column support device.   The steering column support device according to claim 9, wherein the thinning portion is formed by a notch that opens at an end edge of at least one of the cylindrical portion and the side plate portion.   The steering column support device according to claim 9, wherein the thinning portion is configured by a through hole penetrating in a thickness direction of at least one of the cylindrical portion and the side plate portion.   The part which clamps the said cylindrical part of the said bush among the outer peripheral surface of the said tilt pivot axis | shaft, and the internal peripheral surface of the said insertion hole is a cylindrical surface with which a diameter does not change respectively in an axial direction. The steering column support device described.

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